gRNA design and validation for mammalian CRISPR knockouts: delivery challenges

[John64]

I'm a graduate student in molecular biology, and my new research project involves using CRISPR gene editing to knock out a specific gene in a mammalian cell line to study its function in a metabolic pathway. While I'm theoretically familiar with the technique, this is my first hands-on attempt at designing the gRNA and ensuring specificity to avoid off-target effects, which is critical for my experiment's validity. For researchers with practical CRISPR experience, what are your best practices for gRNA design and validation before moving to the actual cell work? What specific challenges did you encounter with delivery methods, like lipofection versus electroporation, and how did you optimize your protocol for editing efficiency and subsequent confirmation of the knockout?